Contrary to the approach followed in civil law jurisdictions, where the taking of evidence is a sovereign function that is primarily performed by the judicial authority, common law jurisdictions, such as the U.S., consider that the collection of evidence is primarily incumbent upon the litigating parties. The civil procedure rules that apply in common law jurisdictions provide for extensive disclosure obligations during the pretrial discovery phase. In situations where the requested information is held by entities or persons in Switzerland, the disclosure obligations that arise under the U.S. (state or federal) procedural rules often conflict with a number of Swiss statutes. This contribution examines and discusses how the tension between the U.S. procedural requirements and the Swiss prohibitions has been, or should be, dealt with both at a national level and under the Hague Conventions dealing with international judicial assistance in civil matters.